The present invention relates to cranes for supporting camera heads, and, more particularly, to a readily assembled and disassembled crane for supporting a camera head.
Supporting systems for cameras used in the filming of motion pictures, television shows, sporting events, award shows and the like, are typically classified into two types, pedestal supports and crane supports. Both types of supports have their advantages and disadvantages. While pedestal supports are often easier to physically move to a new location, they generally have a restricted range motion during filming as the camera is generally rotatably fixed on the pedestal which has restricted movement. Accordingly, crane supports which dispose the camera at the end of a cantilevered boom are often considered more versatile from a film standpoint inasmuch as they offer a range of motion to the supported camera following a curved locus during filming.
Cantilevered cranes for supporting a camera are known in the art (e.g., U.S. Pat. No. 5,033,705 to Reagan and U.S. Pat. No. 5,192,963 to Hill). Some such cranes support both the camera and an operator possibly with an assistant, as shown, for example, in U.S. Pat. No. 2,211,088 to Arnold, U.S. Pat. No. 2,472,944 to Furer, et al., and U.S. Pat. No. 5,683,063 to Seiders et al. Alternately, a camera alone may be coupled to the boom and remotely operated by a camera man disposed, for example, at the proximal end thereof. The camera may be mounted to the distal end of the boom for movement along an arcing path, as shown, for example, in U.S. Pat. No. 2,156,862 to Maugard and U.S. Pat. No. 5,177,516 to Fitz et al., or an arcing and telescoping path as disclosed, for example, in U.S. Pat. No. 4,907,768 to Masseron, et al., and U.S. Pat. No. 4,943,019 to Mester. While some crane supports utilize a simple pivoting motion of the boom about a single point, they typically utilize bulky and relatively complex four-bar linkage arrangements to control the movement of the head supporting the camera at the distal end of the boom (e.g., U.S. Pat. No. 4,657,220 to Lindsay, and U.S. Pat. No. 5,531,412 to Ho).
Although generally relatively large in size, it may be desirable to physically move the location of the crane. Unfortunately, most cantilevered cranes cannot be efficiently moved during camera use without significantly adversely affecting the filmed image. Additionally, most are extremely difficult and time consuming to disassemble and reassemble and, accordingly, cannot be readily transported to different filming locations, increasing production costs and reducing filming flexibility.
In utilizing cantilevered cranes, it is imperative that camera be as stable as possible during movement in order to provide steady and smooth filming. According, it is desirable to minimize any recoil resulting simply from movement of the boom or the crane. Additionally, environmental factors, such as high winds that may be encountered at outdoor events, may likewise affect the quality of the filming provided by a remotely mounted camera. Thus, it is also preferable that the crane be resistant to movement resulting from such environmental factors. Typically, however, cranes which are relatively resistant to these factors are either highly complex in structure, expensive, or extremely heavy and difficult to transport.
A support crane must also maintain the camera in a desired position once determines by the operator. In other words, when the crane is in a desired position, the crane is preferably resistant to drift, or movement from the desired stationary position. In this regard, cranes may include locking mechanisms which physically lock the crane in a desired position. Alternately, if accurately balanced, crane manufacturers may claim that the crane theoretically maintains the remotely mounted camera in a desired position, even without a lock mechanism. Unfortunately, however, the cranes of the prior art typically have fallen short in this regard. Drift is common among support cranes, particularly those more simple designs or those at the lower end of the cost scale.
Accordingly, it is a primary object of the present invention to provide lightweight crane for supporting and articulating a camera. A more specific object is to provide a crane that may be easily maneuvered, quickly assembled and disassembled, as well as be very stable.
An additional object is to provide a crane that readily maintains a position during use and is resistant to drift. A related object is to provide a crane that is rigid.
A further object is to provide a crane that is may be effectively utilized in various circumstances, indoors and outdoors. A more specific object is to provide a crane that is resistant to high winds or the like.
Another object is to provide a crane with high reliability, which can be economically produced.
Other objects and advantages of the present invention will become apparent as the following description proceeds. While the present invention may be described herein principally in connection supporting cameras, it should be appreciated that this invention is equally applicable to supporting other types of recording devices
The invention provides a lightweight crane that may be easily maneuvered, quickly assembled and disassembled, and that is very stable. The crane includes a boom that is balanced upon a pivot tower and supports the user controls at one end and the camera at the other. According to an important feature, the crane is balanced such that it will hold substantially any tilt position once the initial balancing is achieved resisting drift and recoil. According to another important feature, the crane is constructed of multiple lightweight components that may be readily broken down and stored in travel. For example, the boom is constructed of extruded aluminum and includes a substantially triangular cross-section. Added support is provided to the nose, which supports the camera at the end of the boom, by a tension rod which runs the length of the boom extending over a pair of arches and coupled at one end to the nose, and at the other to the pivot tower. The cable additionally acts to maintain the nose assembly in a substantially horizontal position. Multiple cable supports preferably supported by support arms add stability to the boom during use.
Additionally, the multiple lightweight components of the boom may be easily assembled and disassembled. In the preferred embodiment, the ends of the boom sections are provided with a cooperative channel structure. The xe2x80x9cupperxe2x80x9d two sides of the triangular cross-section boom sections are provided with cooperating channels such that gravity assist in assembling the sections. Once seated, a thumb screw, or a screw with a knob is used to couple the xe2x80x9cbottomxe2x80x9d walls of adjacent components together to secure adjacent components to one another. A similar arrangement is used to couple the operator controls to the proximal end of the boom at the boom extender, which supports the counterweight.
Preferably, the boom includes a plurality of openings which extend into the interior of the hollow boom. Not only do these openings further reduce the weight of the boom, inasmuch as they are staggered about the perimeter of the boom, they maintain the structural integrity and strength of the structure. Additionally, significantly, the inclusion of these openings increases the resistance of the boom, and, accordingly, the camera head, to the effects of high winds.
The boom is supported by a pivot tower on a base unit that includes head supported on a quad pod coupled to a wheeled dolly. The pivot tower includes both horizontal and vertical tilt assemblies for facilitating horizontal and vertical pivotal movement to the boom relative to the head. The legs of the quad pod are coupled to both the head and the dolly by pins which are received in the hollow interior of the legs. The head and the dolly are then coupled together by a quad pod tie down rod which effectively compresses the legs, securing the base unit as a whole.
The dolly includes substantially parallel ladder components to which dolly wheels, levelers, a steering arm and steering linkage are coupled. As a result, the operator may either xe2x80x9ccrabxe2x80x9d or xe2x80x9ccirclexe2x80x9d steer the dolly to appropriately position the camera, either prior to or during usage. The ladder components are coupled together by and xe2x80x9cX-shapedxe2x80x9d cross brace to which the quad pod tie down rod is tightened to assemble the quad pod legs and head to the dolly. Upon disassembling the ladder components from the cross brace, the cross brace may be scissored to a relatively flat position for storage. The ladder components may be stored with the wheels, feet and steering linkage attached. Thus, the base unit is easily assembled and disassembled for storage and shipment.
Thus, the invention provides a lightweight crane that may be quickly assembled and disassembled for shipment. Due to its open structure, it is highly resistant to drift, as well as movement due to outside environmental forces, such as the wind. The crane provides reliable, lightweight support for articulation of a camera or the like, at an economical cost.
These and other aims, objectives, and features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.